#!/bin/bash

# Copyright (C) 2003-2021 Free Software Foundation, Inc.

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

cat - <<\EOF > /dev/null
Invoke e.g., like this
VG_PATH_PREFIX=/cu/src/vg: DU1=/cu/src/du DU2=/usr/bin/du ./du-tests
Where /cu/src/vg/du is a valgrind wrapper around du,
and DU1 refers to the just-built du binary you want to test.
EOF

test -z "$DU1" && { echo DU1 envvar not set 1>&2; exit 1; }
test -z "$DU2" && { echo DU2 envvar not set 1>&2; exit 1; }

test -x "$DU1" || { echo $DU1 not executable 1>&2; exit 1; }
test -x "$DU2" || { echo $DU2 not executable 1>&2; exit 1; }

# Expects $DU1 and $DU2 to be the binaries to compare.
d1=$(mktemp -d)
cp -a $DU1 $d1/du
d2=$(mktemp -d)
cp -a $DU2 $d2/du

for args in  \
    '-Sa .' \
    '-Sa ../..' \
    '-Sa a' \
    '-Sa /tmp /t' \
    '-Sa /tmp' \
    '/tmp /t' \
    '-a /tmp /t' \
    '-a a' \
    '-ca .' \
    '-ca ..' \
    '-ca ../..' \
    '-ca /tmp /t' \
    '-ca /tmp' \
    '-ca a' \
  ; do
  echo Args: $args ======================
  diff -u --label=$DU1 --label=$DU2 \
    <(PATH=$VG_PATH_PREFIX$d1 du $args 2>&1) <(PATH=$d2 du $args 2>&1)
done
rm -rf $d1 $d2
